This invention relates to a manually actuated pump which dispenses liquids in measured quantities from the contents of bottles or other containers. The pump is comprised of an actuating handle capable of being axially displaced against the action of a spring, a pump space having its volume reduced on manual actuation, a feeder tube connected therewith, and two valve-closing surfaces that, as a function of the displacement of the actuating handle, alternately open and close the passage leading to the feed tube and the discharge duct of the pump.
Pumps of the above type are known from German design patent DE-GM No. 81 38 264, and comprises two individual valves-namely, a valve flap molded to match the vertical tube, and a lip-shaped valve connected to the discharge duct. Under excess pressure in the pump space, the lips lift from each other, and join each other again during the intake or suction stroke. The functional reliability of such a pump is highly dependent upon the degree of viscosity of the contents to be dispensed. For example, a pasty compound may impair the function of the valve.
Accordingly, it is an object of the invention to design a manually actuated pump with greater functional reliability, thereby allowing a wider range of application to products of varying viscosity.